Board of Fortifications - World War I and Later

World War I and Later

By the time of the First World War, many of the Endicott and Taft era forts had become obsolete due to the increased range and accuracy of naval weaponry and the advent of aircraft. In the 1920s and 1930s, most U.S. coast defense facilities were put on "maintenance" status, a type of "mothballing." In the late 1930s and early 1940s, a new program of construction added huge 16-inch gun batteries, as well as rapid-firing 6-inch and 90 mm guns guns (for use against motor torpedo boats) to many harbors' defenses, and large fields of submarine mines were still being deployed as well. But as it became clearer that the U.S. was unlikely to face seaborne attack, these defenses were largely discontinued (by 1945), and were decommissioned altogether after 1946.